The present invention relates to fluid connectors and, more particularly, to swivelable fluid connectors.
Two very important areas of concern related to pressure confining swivellable joints are the range of temperature over which the joint will safely operate and the corrosion that is experienced by the materials of the two main non-elastomer joint elements. It has been shown that by limiting the change in deformation an elastomer seal is subjected to during operation, the elastomer operational temperature range may be increased, particularly in the low temperature operation. This is very important because formulations of elastomers to achieve lowered temperature operation results in a loss of important mechanical/ physical properties such as abrasion resistance and tensile strength. The materials used to soften the elastomer to provide better "spring back" from low temperature deformation are lost over a period of time shortening seal life. To overcome shortened life, a more expensive elastomer having similar mechanical properties must be used.
The benefits of lower cost, longer life, and better, mechanical properties are gained if a low cost means of limiting the deformation of an elastomer seal during normal performance can be found to replace current means of limiting deformation. The main barrier to achieve these benefits has been the cost of providing the very close fits of the two elements which must swivel with respect to each other.
In high quantity, low cost applications, it is currently the solution to pay more for an elastomer. It is not uncommon to pay 4 to 100 times the cost per pound of elastomer to achieve the desired temperature results.
The present invention shows a very low cost means for achieving the minimal change in elastomer deformation in this class of devices. The means disclosed herein also provides the possibility of a second very important benefit which may be achieved by permitting the use of dissimilar materials for the two elements which swivel relative to each other.
It is possible to separate two dissimilar materials, such as two different metals, in a manner which discourages corrosion even in the presence of an electrolyte or salt-like spray. This is especially appealing because metals are often used in connectors because of their strength under high temperatures. In actual practice this feature can result in very significant cost reductions and improve service life because one of the metal components can be made of an inexpensive material such as steel. In non-swivelling situations, the fixed relationship of two elements which are sealed by an elastomer, give rise to minimum deformation and allow operation at lower temperatures when similar materials are used, however, use of dissimilar materials leads to rapid corrosion.
In a swivelling joint, there are many situations where one element of the joint is attached to a port in a device, and the other element of the swivelling joint must connect to steel tubing for example. If the device with the port to be connected happened to be an aluminum fitting, the fitting would normally corrode quite quickly if it were intimate with a steel element of the joint which is connected to the steel tubing.
It has been found that one may improve both the sealing temperature and the dissimilar metal corrosion by using the means disclosed herein. As an example of the use of the means disclosed the embodiment of an aluminum casting with a port to be pressure confining or excluding connected to a steel tubing in a swivelling connection will be discussed in the figures that follow.
It is an object of the present invention to provide a means by which the operating temperature of an elastomer sealing material may be lowered. It is also an object of ht present invention to reduce corrosion between two dissimilar metal materials in swivelling-type pressure confining or excluding joints.
From the following detailed description taken in conjunction with the accompanying drawings and subjoined claims, other objects and advantages will become apparent to those skilled in the art.